Incandescent body for electric lamps.



' To all whom/2'23 may concern -UNITED "STATES PATENT OFFICE.

WILLIAM G. HUGHES, OF PITTSBURGH, PENNSYLVANIA.

INCANDESCENT BODY FOR ELECTRIC LAMPS.

No Drawing.

Be it known that LNVILLIAM G. HUGHES,

a citizen of the United States, and residing at Pittsburgh, in thecounty of Allegheny and State of Pennsylvania, have invented new anduseful Improvements in Incandescent Bodies for Electric Lamps, of whichthe following is a specification.

The invention has for its object the production of an incandescingfilament for incandescent electric lights or lamps which is composed ofsubstantially pure uranium.

Another object of my invention. is to provide a filament ofa toughfibrous nature which will be less liable to fracture than filamentscomposed of material which is of I will afford increased ,candle powerin the lamp with less consumption of current.

Incandescing filaments in accordance with my invention may bemanufactured in accor-dance with different processes, the preferredoneof which will be hereinafter described.

In accordance with the preferred process for obtaining the metallicuranium, I'take, in substantially proportions herein given, uraniumchlorid 7 5 grains, metallic sodium (finely divided) grains, andpotassium chlorid 150 grains. I place these substances, in layers, in aporcelain or alundum crucible, and cover the crucible contents withpotassium. I then place this crucible with its contents in an ironcrucible of a size to provide a space between the two crucibles, and Ifill this space between the inner and outer crucible with clean brokenor granular carbon. I then seal the iron crucible and subject the wholeto a high temperature suflicient to produce a white heat. This sets up athermo-chemical action with the result that the metallic uranium isformed or settles in the bottom of the inner crucible.

After obtaining the uranium metal, it is Specification of LettersPatent. Patented Aug, 11, 1914;, Application filed December 16, 1912.Serial No. 737,038.

process, in the absence of air, after which it.

is drawn into Wire by any of the Well-known processes by which it isshaped for filament use. As an example of one method of annealing andone of drawing the uranium, the

thus annealed, the uranium which is in pure metallic form, is drawn intoa filament by first passing it through grooved rolls to reduce it towire-like form, is then re-annealed in any preferred manner, as forexample, byv the procedure above outlined and is then drawn throughsuitable dies, the

final or finishing die being constructed from g a diamond or othersuitable jewel.

In accordance with my invention, the filament is composed solely ofdense coherent metallic uranium having an extremely high fusing fi pointand capable of great incandescent e ciency at a coinparatlvely low Wattrate per candle power, and free from perceptible disintegration at suchefficiency.

Having fully described -my invention, what I claim is 1. A filament forincandescent lights composed of. drawn uranium in pure metallic state.

2. A filament for incandescent lights com- WILLIAM HUGHES.

Witnesses:

IDA L. CHERRER, IONA WAGNER.

